Need advice to develop 4x5" films for ZS

**Louis bacou** · 21-Apr-2011, 15:14

Hi am French Photographer
Apologise if sometimes my english language is not really perfect
So is anybody can help me to calibrate film 4x5" HP5
today I use ultrafin tetenal
Have a jobo cpp2a
N is 4'15" degree 20
N+1 is N time 25% plus
N+2 is N time 60% plus
N-1 is N time 15% less
N-2 is N time 25% less
Looking forward to get some advices
Kind regard
Louis

**Joanna Carter** · 21-Apr-2011, 16:26

Est-ce que vous connaissez les forums Galerie-photo. Vous y trouverez beaucoup de photographes francophones s'il vous conviendrait mieux

**Philippe Grunchec** · 22-Apr-2011, 07:51

Bonjour Louis ! Appelez-moi un de ces jours prochains !

**Louis bacou** · 24-Apr-2011, 14:56

Bonjour Philippe quelle surprise
Je vous tel dès mon retour sur Paris
Cordialement
Louis

**Louis bacou** · 24-Apr-2011, 15:15

Hi Joanna
Many thanks to reply so quick
Of course I know Galerie-photo
But sometimes is as well to get advices from others photographers
Regards

**Doremus Scudder** · 25-Apr-2011, 02:00

Louis,

Sorry, Je ne parle pas français, mais...

If I might ask: How are you arriving at your time for N development and your percentages for the plus and minus times? And, what is your personal E.I.?

The Zone System requires that you test for your personal Exposure Index (E.I. = film speed) and development times yourself. You can use others' data as a starting point only. There is no "standard" way, since everyone's technique is different. If you are asking, "are these figures correct?" then there is no right answer.

Are the figures you gave from your own testing, or, if not, where did you get them? It's hard to know how to help unless we know.

Best,

Doremus Scudder